Sauté 1 chopped white onion in 3 Tbsp oil until soft. Drain beans. Add beans a little at a time. Mash with a potato masher after each addition (beans are easier to mash when warm). Continue until all the beans have been mashed. To keep the beans from becoming dry, add broth as needed. Add green chilies, garlic powder, salt, & cheddar cheese. Heat to blend flavors. Serve as a side dish. Garnish with shredded cheese.